Iron golf club head

ABSTRACT

There is provided an iron golf club head comprising a head body and a face plate made of a highly resilient metal which is attached to a front face of said head body, wherein a thick-walled portion is formed in the lower central part of said face plate; multiple narrow ribs are formed to radially extend from said thick-walled portion toward the upper and lateral peripheral parts of said face plate, said ribs having a thickness not substantially exceeding the thickness of said thick-walled portion; and broad thin-walled portions are formed between said adjacent ribs.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority upon Japanese Patent Application No. 2002-19394 filed on Jan. 29, 2002, which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to an iron golf club head which has a face plate made of lightweight metal such as a titanium alloy attached on a front face of a head body.

[0004] 2. Related Art

[0005] As disclosed in Japanese Patent Application Laid-open Publication No. Hei 9-192273, a conventional iron club head has achieved an improved resilience by making a central portion of the face plate thick, and making a perimeter thereof thin.

[0006] However, since this conventional iron club head has the thickened center portion of the face plate, the center of gravity of the entire head is situated at a relatively high position so that the moment of inertia of the club head is reduced by this high position, which therefore impairs ease of swing for players.

[0007] The present invention has been made in view of the above problems, and its object is to provide a golf club head which, while maintaining high resilience, accomplishes to provide a low center of gravity through lowering the weight distribution of the entire head, and thus provides a large moment of inertia of the club head for a high trajectory and ease of hit.

SUMMARY OF THE INVENTION

[0008] In order to achieve the above and other objects, the present invention provides an iron golf club head comprising a head body and a face plate made of a highly resilient metal attached to a front face of the head body, the face plate comprising a thick-walled portion formed in a lower central part thereof, a plurality of narrow ribs formed to radially extend from the thick-walled portion toward an upper and lateral peripheral parts of the face plate, each rib having a thickness not substantially exceeding a thickness of the thick-walled portion, and a plurality of broad thin-walled portions formed between the ribs arranged adjacent to each other.

[0009] The thick-walled portion in the lower central part of the face plate may have a substantially semi-circular shape with a linear section of the semi-circle located on the side of a sole section, and the plurality of ribs are formed to radially extend from an arc section of the semi-circle

[0010] The thin-walled portions disposed between the plurality of ribs may be formed by pressing each thin-walled portion so that each thin-walled portion has an inner end with an arc of a smaller radius and an outer end with an as arc of a larger radius respectively. For example, the thin-walled portions may be formed by pressing so that each thin-walled portion is shaped in an eggplant-like profile.

[0011] The thick-walled portion and the narrow ribs may be formed with a thickness in the range of 2.7 mm to 3.5 mm, and the thin-walled portions are formed with a thickness in the range of 2.0 mm to 2.6 mm.

[0012] A back side of the head body may be enclosed by a rear face plate to form a hollow body structure.

[0013] Weight members may be disposed in toe and heel sides in a lower back side of the head body.

[0014] The face plate may be formed of a titanium alloy.

[0015] According to another aspect of the present invention is provided an iron golf club having a golf club head comprising a head body and a face plate made of a highly resilient metal attached to a front face of the head body, the face plate comprising a thick-walled portion formed in a lower central part thereof, a plurality of narrow ribs formed to radially extend from the thick-walled portion toward an upper and lateral peripheral parts of the face plate, each rib having a thickness not substantially exceeding a thickness of the thick-walled portion, and a plurality of broad thin-walled portions formed between the ribs arranged adjacent to each other.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings wherein:

[0017]FIG. 1 is a plan view of a golf club head according to one embodiment of the present invention, seen from a front side, and shows a concave-convex pattern on a back side of a face plate drawn in solid lines for convenience in explanation;

[0018]FIG. 2 is a front view of a golf club head in FIG. 1 of the present invention; and

[0019]FIG. 3 is a cross sectional view in the center of a face plate of the golf club head depicted in FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE INVENTION

[0020] A preferred embodiment of the present invention will be described hereinafter with reference to the accompanying drawings.

[0021]FIG. 1 and FIG. 2 are drawings of the iron golf club head of the present invention as seen from its front side. In FIG. 1, for the sake of explanatory convenience, the concave-convex pattern on the surface of the back side of the face plate is shown in solid lines. FIG. 2 shows the front side of the face plate. FIG. 3 is a cross sectional view taken along the center of the golf club head of FIG. 2.

[0022] The golf club head of the present embodiment basically comprises a head body 1 cast from stainless steel and having an opening to the front face, and a face plate 2 formed from a 6-4 alloy of titanium and fitted to the opening of the head body 1.

[0023] The head body 1 is cast in one body which comprises a flange section 3 extending along the periphery from the top side to the toe side thereof, a thickened sole section 4, a heel section, a hosel section 6, and a rear face plate 5 extending from the inner peripheral edges of these sections. The front face of the head body 1 is open so that the head body 1 has a hollow body structure. A face plate 2 is integrally attached, for example by welding, to the opening of the head body 1.

[0024] On the toe and heel sides in the lower back side of the head body 1 are provided hollow cylindrical holes which are substantially U-shaped, and in these hollow cylindrical holes are inserted tungsten blocks 7 as weight members.

[0025] A substantially semi-circular thick-walled portion 8 with the linear section of the semi-circle located on the side of the sole section 4 is formed in the lower central part of the face plate 2 which includes a sweet spot; and a plurality of ribs 9 are formed to radially extend from substantially equally spaced points along the circumferential direction of the arc-shaped section of the semi-circle, towards the periphery of the face plate. The parts formed between the ribs 9 are thin-walled portions 10. As shown in FIG. 1, each of the thin-walled portions has an inner and an outer end which form arcs of a smaller and a larger radius respectively. In other words, it has an eggplant-like shape in front view. The thin-walled portions 10 are formed by pressing, and therefore the boundary part of the eggplant-like shape is curved and each of the shapes is recessed in. The width of the ribs between the adjacent thin-walled portions 10 is as narrow as about 1.5 mm.

[0026] The thickness of the thick-walled portion 8 in the lower central part of the face plate and the ribs is in the range of 2.7 to 3.5 mm, for example 3.0 mm, and the thickness of the thin-walled portions 10 is in the range of 2.0 to 2.6 mm, for example 2.5 mm.

[0027] As apparent from the above description, the iron club head of the present embodiment is constructed such that the thick-walled portion 8 of the face plate 2 is located below its center, and the center of gravity can be made lower than that of a conventional club head. Furthermore, the club head of the present embodiment is constructed such that the thick-walled portion including the sweet spot, is surrounded by the thin-walled portions 10 which extend in the outer part of the face plate and which are reinforced by the narrow rib. Therefore, the club head can have a desired strength and, at the same time, can ensure high resilience.

[0028] As described in the preferred embodiment of the present invention, by providing the hollow body structure in which the back side of the head body is enclosed by the rear face plate 5, and by inserting weight members 7 made of, for example, tungsten, in the toe and heel sides in the lower back side of the head body 1, the center of gravity of the entire club head can be located more towards the rear (deeper in the depth direction), and lower than that of a conventional iron club head, and, therefore, the present embodiment can provide a golf club which attains a high trajectory for improved distance and ease of swing due to the lower center of gravity design. Further, since a large moment of inertia of the club head is achieved through its low center of gravity which is attained by lowering the weight distribution of the entire head, the present embodiment can provide a golf club which accomplishes a high trajectory and ease of hit.

[0029] Although the preferred embodiment of the present invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made therein without departing from the spirit and scope of the inventions as defined by the appended claims. 

What is claimed is:
 1. An iron golf club head comprising a head body and a face plate made of a highly resilient metal attached to a front face of said head body, said face plate comprising: a thick-walled portion formed in a lower central part thereof; a plurality of narrow ribs formed to radially extend from said thick-walled portion toward an upper and lateral peripheral parts of said face plate, each said rib having a thickness not substantially exceeding a thickness of said thick-walled portion; and a plurality of broad thin-walled portions formed between said ribs arranged adjacent to each other.
 2. An iron golf club head as claimed in claim 1, wherein said thick-walled portion in the lower central part of said face plate has a substantially semi-circular shape with a linear section of the semi-circle located on the side of a sole section, and said plurality of ribs are formed to radially extend from an arc section of the semi-circle.
 3. An iron golf club head as claimed in claim 1, wherein said thin-walled portions disposed between said plurality of ribs are formed by pressing each said thin-walled portion so that each said thin-walled portion has an inner end with an arc of a smaller radius and an outer end with an as arc of a larger radius respectively.
 4. An iron golf club head as claimed in claim 1, wherein said thin-walled portions disposed between said plurality of ribs are formed by pressing so that each said thin-walled portion is shaped in an eggplant-like profile.
 5. An iron golf club head as claimed in claim 1, wherein said thick-walled portion and said narrow ribs are formed with a thickness in the range of 2.7 mm to 3.5 mm, and said thin-walled portions are formed with a thickness in the range of 2.0 mm to 2.6 mm.
 6. An iron golf club head as claimed in claim 1, wherein a back side of said head body is enclosed by a rear face plate to form a hollow body structure.
 7. An iron golf club head as claimed in claim 1, wherein weight members are disposed in toe and heel sides in a lower back side of said head body.
 8. An iron golf club head as claimed in claim 1, wherein said face plate is formed of a titanium alloy.
 9. An iron golf club having a golf club head comprising a head body and a face plate made of a highly resilient metal attached to a front face of said head body, said face plate comprising: a thick-walled portion formed in a lower central part thereof; a plurality of narrow ribs formed to radially extend from said thick-walled portion toward an upper and lateral peripheral parts of said face plate, each said rib having a thickness not substantially exceeding a thickness of said thick-walled portion; and a plurality of broad thin-walled portions formed between said ribs arranged adjacent to each other. 